Improvement in sewing-machines



J. W. HOWLETT. SEWING MACHINE.

bld-31,601. Patented Mar. 51'861.

PATENT OFFICE.

lJ. HOWLE'IT, OF ,GREENSBOROUGH, NORTH CAROLINA.

IMPROVEMNT iN SEWING-MACHINES.

Specification forming part of Letters Patent No. 31,601, dated March 5, 1861.

To dit whom it may corwcrn.- i i Ble it known that I, J. W. HOWLETT, of

4 Grecnsborough, in the county of Guilford and State of North Carolina,have invented a new and useful Improvementin Sewing-Machines; and I do hereby-declare that the-followingisa full, clear, and exact description ofthe same, referencebeing had tothe accompanying drawings,g,iormin g a part of this specification, in which- 4 -Figure 1 represents a side view and partial central section, Fig. 2 a plan, and Figs. 3, 4, 5,6, and 7 various details, of the machine.

Sirilar letters of reference in,each of the several gnres indicate corresponding parts.

The natureof my invention consists, lfirst, in producing the necessary tension ofthe upper-needle thread by passing it between the glass plates held in dovetailed slots at the ends of a-bent spring, when this spring is combinedv with an adjustable clampf'screw, lin

the manner and forthe purpose hereinafter described.

. It consists, second', in making thetensionvplates of glass, for the purpose hereinafter deshaft operates the end P ot' .the lever or arm- O, carrying the lower and horizontal needle,

S. Q is the fulcrnm of the 'lever' 0 P. 'The upper needle, T, works vertically and the lower needle, S, horizontally. A forked projection, Z, extends from the under face of the platform of the machine, and a small, rod, WV works horizontally through a hole in the back Z- jof said projection. A spiral spring, Y, presses saidrod forward, 'so as to cause a stoppin,-X, inserted through the rod, to bear against the rear' face. of the back Z of said projection. The end of the rod extending forward between the forked ends of the projection Z is provided with a smooth face, U, 'tapering at the end nearest the horizontal needle S, asseen at V. This d'eviceiissc ar ranged in relation to needle S that the latter Ias it advances meets the tapering end V and presses the face U slightly back against the tendency of spring Y. By this means the loop of needle S is thrown forward, so that the vertical needle T, as it descends, is ina-de to -pass through said loop without any possibilt ty of 'failing to pass through the loop and thereby causing a drop-stitch.

The device for feeding the cloth in such manner as to determine any desirable length of stitches is asl follows: A horizontalbar, E, slides at one end4 through a slot in a projection, J, extending from the under face of the latform, the end of vthe bar bearing against a spring, K. The slot J allows this end ofthe bar a very slight vertical play, as this slot serves' as a fulcrum for the motion in a vertical planeof the other end or" the bar. lhis motin is produced by an eccentric pin, B, at .the forward end of shaft A, playing through a horizontal slot, C, in a'wing, D, extending from the undersurface of the bar E. A setscrew, I, works through a female screw in the rim of the platform. The smooth-end of this set-screw extends through a washer, G, into a vertical slot, F, in the bent-down end of arm E. The. end -of the screw-threaded portion oi' I bears against the washer G. By screwing the screw I in as far as it willgo, as seen in Fig'. 3, the end of the screw-thread of I, bearing against washer G, presses the bar E back against spring K far enough to clear the inner endof slot G of the pin B. In this case the eccentric ypin B, playing in the slot. C, will Inerelymove the wing D and this end of arm E ve tically up and down, thereby producing no. feed motion at all. By screwing the screw I out the inner end ot' slot G is brought more or less within reach of the pin B rand the wing D, and this end of arm E will thereby receiveI a combined horizontal and vertical motion. It the screw I is screwed outfar enough to bring the inner end of slot C within reach cf the -wholc extent of the circular motion of pin B,

ltion, and the o'ther.end slides horizontally through slot `J, any point Abetween 'must describe auelliptical line ofy more'or less eccentrcity, according to the abovedescribed adjustment ofthe set screw I., A clamp, N,

` vantages of -this feed device, besides its sim-v plicity of construction, is that it works entirely without noise.

The driving-pulley c', providedl around its rim with an india-rubber face, D', turns loose on the outer end of the driving-shaft A. A disk provided with an arm, E', tits the cavity inside of the .rim-,of pulleyl G'. keyed to shaft A. An india-'rubber dog, G", is pivoted inside of the disk, atH, and extends through. a' slot, F, -iu the rim of the disk. When the pulley C' is revolved inthe proper direction for operating the machine (see arrow iuFig'. 4) theknob X', projecting from the iusideof the rim of pulley C' into a circularl groove, Y', in theface of rim E', comes to bear against dog G', the latter'being in the position shownin Fig. v5, an thus causes thedisk and shaft-A to revolve t gether. with the pulley C; but if revolved u the other direction the knob strikes the-rear face of -dog Gr' and turns the dog voutot' the way, as indicated by thedotted arc I' in Fig. 5, so that the disk andshaft A will stand still while the pulley revolves. The advantage of this device is that itworks'without noiseaud sudden jars, and without danger of breaking anythingon suddenly setting the machine in motion.

The disk isv A- bent spring, J', is arranged ona pivot, K', on top of theupper-needle armB', and can be pressed together more or less by operating a clampmut, L', at the upper and' screw-thread? ed end of the pivotK'. The outer ends of the spring-are medew-ith dovetail elots,iuto which two plates of glass, M' M', arc inserted. The

thread of the upper needle passes from the spbolbetweeu these glass plates, which are pressed together by means of the clampmut L, so as to impart the proper tension to the needle-thread. -The great smooth-ness and hardness of glass makes it far superior to any other material for the purpose. The thread will notbeinjnred while passing through these glass plates, andthe plates will never wear out, asis thecase with other materials einp'loyed for the purpose.

Y What I claim as my invention, and desire to secure by Letters Patent, is

1. Producing the necessary tension 'of the upper-needle thread N' by passing it between two glass plat es,'M' M', held in dovetail slots at theend of a bent spring,J,1whcn this spring is combined with an adjustable clamp-screw,

L', substantially as and for the purposes set forth. l

2. Making the tension-plates of glass, substantiallyas and for the purposes setforth.

The arran lement of rod, `W, witha tapering face,

J. W. HoWLncrr;

Witnesses: i W. C. DONNELL,

J ouN F. How-LETT.

V, and spiral spring Y, in' .combination with a vertical and horizontal re` 

